The present invention relates in general to fuel filters with a water separation capability and the cooperating components and subassemblies used with such fuel filters. More specifically the present invention relates to the design of a water drain valve for draining accumulated water from within a fuel filter which is designed with a water separation capability. As used herein, the reference to a "drain" includes the flow passageway from the filter housing into the drain valve and the outlet passageway or aperture of the drain valve which empties the draining water from the drain valve. The structural remainder of the drain valve controls the flow of water from the flow passageway of the filter housing to the outlet passageway of the drain valve. Venting air is introduced by the drain valve as the water empties.
One of the concerns when draining accumulated water is the possibility that there will be a spillage of fuel from the drain valve. There are also design considerations in the construction of water drain valves including how to vent the drain valve. Related to the venting consideration is whether a check valve is needed so that drainage does not occur until the drain (valve) is deliberately opened in order to drain the accumulated water.
Whatever the desired specifics might be for the design of the drain valve, the aspects of reliability, ease of use, and low cost remain important considerations. The present invention provides the novel design of a water drain valve which takes into consideration each of these important considerations. In addition, the water drain valve of the present invention provides a vented, water drain valve which is suitable for use in both non-pressurized and pressurized configurations without the unwanted spillage of fuel. The water drain valve of the present invention is also designed without the added cost of a check valve. These various design features are enabled by combining the vent portion of the assembly into a drain port by way of a separate passageway to provide atmospheric air for venting. All of this is configured in a novel and unobvious manner.